Modification of AODV for enhanced data delivery

Abstract

A Mobile ad hoc network (MANET) is a self-configuring network of mobile devices connected by wireless links. In MANET, all the nodes can move freely and independently, so topology is highly dynamic. The communication in MANET is uncertain because established route could be broken anytime. In this paper, we proposed a scheme to establish a more stable route during the route discovery process and once the route gets established, we tried to minimize its breakage probability. The major cause of route breakage in MANET is dynamic movement of mobile nodes themselves and other might be nodes running out of their battery power. By considering these two factors, proposed scheme tries to involve only those nodes in the active route that have sufficient battery power and make ensure that neighboring nodes of the established route are not too much far from each other. After the route gets established, proposed scheme tries to avoid its breakage by preparing a backup route just-in-time before the link breaking. For it, each node makes use of two levels of thresholds for each: node's remaining battery power and power of the RF signal received from its neighboring node. Each node, that is the part of active route, investigates its battery power & received signal power all the time. When any investigating factor drops to higher level of threshold for a node, two route discoveries gets initiated to find a backup route. One route discovery is always b/w upstream node & closest downstream node of effected route while second route discovery depends upon the location of vulnerable node relative to source and destination. The optimal discovered backup route becomes the primary route when lower (critical) level of threshold is met. A close analysis of the proposed scheme shows that it improves the packet delivery fraction and reduces end-to-end delay for data packets.